American imperialism was fueled by several different factors including social Darwinism, the desire to spread democracy, and access to natural resources. Social Darwinism is the belief in the "survival of the fittest." This concept was adapted from Charles Darwin's scientific studies regarding birds in the Galapagos Islands. Social Darwinism focused on the idea that the strongest individuals and countries were bound to take over weaker individuals and countries. Along with this, America wanted to spread the idea of democracy to other territories, as they thought it was the best government system to use. Lastly, gaining new territories would allow America access to new natural resources.
This is why America acquired territories like Hawaii. Hawaii was a territory that had an abundance of sugar, an important commodity to American citizens. To gain Hawaii, America helped the native citizens to overthrow their Queen. Along with Hawaii, the federal government decided to annex Alaska as well. This paid off well, as there was a huge amount of gold found in this territory. This land was purchased by the federal government from Russia.